Conventionally, welding apparatuses that irradiate a target with laser light and cover a laser light irradiation position (welded portion) on the target with inert gas have been used. The laser light irradiation position is covered with the inert gas in this manner, thereby preventing oxidization of the welded portion.
In the welding apparatuses of this type, when fume generated from the target by irradiation with the laser light passes through the laser light, intensity of the laser light is lowered in some cases. To provide a welding apparatus and a nozzle device capable of preventing the lowering of the intensity of the laser light due to the fume is meaningful.